Twisted guard rail and debris line road side where tour bus careened off a mountain highway and plunged down a snow-covered slope, killing nine passengers and injuring at least 27 others, in Oregon December 31, 2012. The charter bus was carrying about 40 people through the Blue Mountains of northern Oregon en route from Las Vegas to Vancouver, British Columbia, when it crashed through a guard rail on Interstate 84 on Sunday morning, authorities said. REUTERS/Steve Dipaola (UNITED STATES - Tags: DISASTER TRANSPORT)

Twisted guard rail and debris line road side where tour bus careened off a mountain highway and plunged down a snow-covered slope, killing nine passengers and injuring at least 27 others, in Oregon December 31, 2012. The charter bus was carrying about 40 people through the Blue Mountains of northern Oregon en route from Las Vegas to Vancouver, British Columbia, when it crashed through a guard rail on Interstate 84 on Sunday morning, authorities said. REUTERS/Steve Dipaola (UNITED STATES - Tags: DISASTER TRANSPORT)